Fisheries Benefits of Marine Managed Areas in Hawaii
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Fisheries benefits of Marine Managed Areas in Hawaii Alan Friedlander Herman Cesar 30 April 2004 Alan M. Friedlander NOAA, National Ocean Service, National Centers for Coastal Ocean Science - Biogeography Program & Oceanic Institute Makapu‘u Point/41-202 Kalanianaole Hwy, Waimanalo, Hawai‘i 96795. E-mail: [email protected] Herman Cesar Cesar Environmental Economics Consulting Kastanjelaan 9 6828 GH Arnhem The Netherlands E-mail: [email protected] Web: www.ceec.nl 2 Fisheries Benefits of MMAs Contents 1. Introduction 3 2. Marine Protected Area Theory and Empirical Evidence 5 3. Description of Study Sites 12 4. Empirical Information On Fish Assemblage Characteristics 17 5. Empirical Information on MPAs in Hawaii – Overall Comparison of Protected Areas 22 6. Recommendations for Modifications to Existing MPAS and for the Design and Siting of Future Protected Areas 25 7. References 31 Appendix I. Top ten species observed on transects for the Six Study Sites 37 Colophon This study is part of a larger report with the title “Assessment of Economic Benefits and Costs of Marine Managed Areas in Hawaii" by Herman Cesar, Pieter van Beukering and Alan Friedlander. This publication is a result of research carried out by Cesar Environmental Economics Consulting (CEEC) and funded by the National Oceanic and Atmospheric Administration, Coastal Ocean Program, under awards NA 160A2412 to the University of Hawaii for the Hawaii Coral Reef Initiative Research Program. Co- funding was obtained from the Division of Aquatic Resources (DAR) and the Department of Business, Economic Development & Tourism (DBEDT). This specific study was compiled by Alan M. Friedlander, under a subcontract with CEEC. 2 Fisheries Benefits of MMAs 3 1. Introduction Declining fisheries resources worldwide and in Hawaii Fish and other harvested resources provide economic, social, cultural, and spiritual benefits to people throughout the world. Global fisheries have undergone enormous changes in the past several decades with three-quarters of the world’s major fisheries now considered to be harvested at or beyond their maximum capacity (FAO 2000) despite increased regulation in most fisheries sectors. The U.S. has some of the most highly regulated fisheries in the world with substantial investments in science, management plans, monitoring, and enforcement (Eagle et al. 2003), yet 40% of U.S. fisheries are considered overfished (NMFS 2002). Examples include the collapse of cod stocks off New England and Canada, which has led to large-scale ecosystem-wide changes, and economic collapse of many coastal communities in these areas (Kurlansky 1998). Because selective fishing can affect a number of population characteristics (e.g. size and age composition, sex ratio, genetic make-up, and large-scale behavioral phenomena like spawning aggregations) those fish that remain may pass on less- preferred characteristics that may confound future fishing efforts (Sladek Nowlis and Friedlander 2004a). In addition to overexploitation, a variety of factors such as habitat loss, climate change, and natural variability have contributed to the collapse of many fisheries. Regardless of the causes, declining fish stocks have had negative economic, social, and ecological consequences at an unprecedented scale. Large marine vertebrates such as whales, sharks, turtles, groupers, and manatees were once important components of marine ecosystems worldwide but have been systematically removed from the ocean by humans over the pat 500 yr (NRC 1995, Jackson et al. 2001, Pitcher 2001). Large predatory fish have been reduced to one-tenth of their historic abundance (Myers and Worm 2003) and these top predators have specialized niches that when depleted can lead to a phase transition of ecosystems dominated by lower trophic guilds (Pauly et al. 1998, Pinnegar et al. 2000). The ‘shifting baseline syndrome’ (Pauly 1995, Sheppard 1995) makes it difficult to determine what constitutes a natural ecosystem and how to mange these ecosystems accordingly. As is the case elsewhere throughout the world, coastal fisheries in Hawai‘i are facing unprecedented overexploitation and severe depletion (Shomura 1987, Smith 1993, Gulko et al. 2000, Friedlander 2003, Lowe 2003). This decline in fish abundance and size, particularly around the more populated areas of the state, is likely the cumulative result of years of chronic overfishing (Shomura 1987; Gulko et al. 2000; Friedlander and DeMartini 2002). Fishing pressure on nearshore resources in heavily populated areas of the main Hawaiian Islands (MHI) appears to exceed the capacity of these resources to renew themselves (Smith 1993). Fish assemblages in the northwestern Hawaiian Islands—a remote area that experiences only limited fishing activity—are dominated by large apex predators, such as sharks and jacks that likely have a profound impact on the structure of the entire coral reef ecosystem (Friedlander and DeMartini 2002). The near- extripration of apex predators and heavy exploitation of lowed trophic levels in the MHI from intensive fishing pressure has resulted in a stressed ecosystem that does not contain 3 4 Fisheries Benefits of MMAs the full complement of species and interrelationships that would normally prevail (Friedlander and DeMartini 2002) (Figure 1) Figure 1: Lightly fished areas in the Northwestern Hawaiian Islands contain greater biomass of all trophic guilds than sites in the main Hawaiian Islands (data from Friedlander and DeMartini 2002). The difference is especially large for apex predators, which account for the majority of all biomass in the Northwestern Hawaiian Islands. Factors contributing to the decline of inshore fisheries in the MHI include a growing human population, destruction or disturbance to habitat, introduction of new fishing techniques (inexpensive monofilament gill nets, SCUBA, spear guns, power boats, sonar fish finders), and loss of traditional conservation practices (Brock et al. 1985, Lowe 1996, Birkeland and Friedlander 2002, Friedlander et al. 2003). The proliferation of long and inexpensive gill nets has allowed new fishers to enter the fishery and set nets deeper and in locations not previously harvested (Clark and Gulko 1999). Intensive fishing pressure on highly prized and vulnerable species has led to substantial declines in catch as well as size and has raised concerns about the long-term sustainability of these stocks (Friedlander and Parrish 1997, Friedlander and DeMartini 2002, Friedlander and Ziemann 2003, Tissot and Hallacher 2003, Tissot et al. 2004). Despite the opinion of many fishermen that overharvesting is one of the major reasons for the long-term decline in inshore marine resources, there is poor compliance with state fishing laws and regulations (Harman and Katekaru 1988). The lack of marine-focused enforcement and minimal fines for those few cases that have been prosecuted contribute to a lack of incentive by the population to abide by fisheries management regulations. Under-reporting by commercial fishers and the existence of a large number of recreational and subsistence fishers without licensing or reporting requirements have 4 Fisheries Benefits of MMAs 5 resulted in uncertainty in actual fisheries catch statistics for the state (Lowe 1996). The nearshore recreational and subsistence catch is likely equal to or greater than the nearshore commercial fisheries catch, with more species taken using a wider range of fishing gear (Friedlander and Parrish 1997, Gulko et al. 2000, Everson and Friedlander 2003). Why has conventional management failed? Sustainability and biodiversity conservation are cited as objectives of ecosystem management (National Research Council 1999) yet current management regimes have failed to meet these objectives. Failures in management can be linked to uncertainties due to incomplete knowledge of populations, communities, and ecosystems (Fogarty et al. 2000). Traditional western concepts of fisheries management (maximum sustainable yield, growth overfishing, recruitment overfishing, etc.) have their genesis in single- species population dynamics and stock assessment (Murawski 2000). This approach is primarily concerned with the conservation of the parts as opposed to the interrelationships among them. Many management tools—including size limits, gear limits, quota systems on effort or total catch, and even temporary closures—are used frequently but do not create a refuge for populations, habitats, and ecosystems, nor do they reallocate fishing effort across space (Sladek Nowlis and Friedlander 2004a). The failure of these more conventional management tools is apparent in the status of fished populations around the world. Several challenges contribute to these management failures, including excessive fishing capacity (FAO 2000), environments degraded by fishing and other activities (Watling and Norse 1998), and management systems that require far more information than is available (NRC 1998; PDT 1990; Sladek Nowlis and Bollermann 2002). Another concern is the possibility of critical depensation (Allee effect) where the per capita birth rate declines at low populations because, for example, of the increased difficulty of finding a mate (Allee 1931). 2. Marine Protected Area Theory and Empirical Evidence Because of the generally poor state of fisheries worldwide, marine resource managers are inspired to consider fresh tools to stem the decline in global fish stocks (FAO 1999). Marine ecosystems are complex with highly variable natural replenishment and therefore